It's just that ASan detects errors on a best effort basis, and it's harder to detect a buffer overflow past the buffer's redzone. On the other hand, such errors are quite rare.
On Tue, May 2, 2017 at 3:34 PM, Aayushi Agrawal <aayushigr...@gmail.com> wrote: > So is this a kind of issue which is not handled by address sanitizer ? > > On 02-May-2017 5:45 pm, "'Alexander Potapenko' via address-sanitizer" > <address-sanitizer@googlegroups.com> wrote: >> >> Most certainly the access to global_array[200] ends up touching a >> valid location in g[], and the access to g[200] lands somewhere in a >> region that has a shadow value of 0. >> Unfortunately ASan can only detect a buffer overflow if the memory >> access touches unaddressable memory (i.e. that with non-zero shadow). >> >> On Tue, May 2, 2017 at 2:09 PM, Aayushi Agrawal <aayushigr...@gmail.com> >> wrote: >> > Hello >> > >> > Here is code snippet - >> > >> > int global_array[101] = {-1}; >> > char g[101] = {-2}; >> > >> > int main(int argc, char **argv) { >> > global_array[atoi(argv[1])] = 70; >> > g[atoi(argv[1])] = 'c'; >> > >> > } >> > >> > If I compile it with clang , address sanitizer and no other flags used >> > then >> > for input as "101" it gives ASAN buffer overflow message but input as >> > "200" >> > does not show any buffer overflow why ? >> > >> > >> > Aayushi >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups >> > "address-sanitizer" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> > an >> > email to address-sanitizer+unsubscr...@googlegroups.com. >> > For more options, visit https://groups.google.com/d/optout. >> >> >> >> -- >> Alexander Potapenko >> Software Engineer >> >> Google Germany GmbH >> Erika-Mann-Straße, 33 >> 80636 München >> >> Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle >> Registergericht und -nummer: Hamburg, HRB 86891 >> Sitz der Gesellschaft: Hamburg >> >> -- >> You received this message because you are subscribed to the Google Groups >> "address-sanitizer" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to address-sanitizer+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "address-sanitizer" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to address-sanitizer+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg -- You received this message because you are subscribed to the Google Groups "address-sanitizer" group. To unsubscribe from this group and stop receiving emails from it, send an email to address-sanitizer+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.